1. Field of the Invention
The present invention relates generally to animal husbandry, and in particular to a portable apparatus for use in connection with treating and weighing livestock.
2. Description of the Related Art
In livestock operations it is often necessary to restrain or direct the animals for palpating, immunizing, branding, treating, weighing, loading, etc. Corrals, loading chutes, alleyways, pens, and the like, have heretofore been constructed and employed by cow-calf operators, steer operators, and large animal veterinarians for these purposes. These structures are often constructed permanently of fence materials, such as stone, barbed wire, wood rails, steel pipe, and the like. However, the capital investment required for such permanent structures is often prohibitive to decentralized ranch operations, particularly those that run livestock on relatively small, isolated tracts of grazing land. Furthermore, many ranchers lease, rather than own, their grazing land and naturally wish to avoid making permanent, fixed improvements.
A common solution to this problem is to physically transport the animals to a location having the necessary permanent, fixed equipment. However, transporting a herd of large animals tends to be relatively time-consuming and expensive. For example, a round trip from a grazing pasture to a treatment area requires loading, transporting, and unloading the animals twice. Naturally, the time and expense associated with transporting livestock herds increases with the distances and the number of animals involved.
A solution to the aforementioned problems is to provide portable livestock working equipment. For example, my previous Letters Patent, U.S. Pat. No. 4,829,936, discloses a portable animal handling unit with retractable transport wheels. The unit provides animal holding passages and chutes for a variety of animal handling and working operations.
A disadvantage with many prior art portable animal handling devices is that large animals can be hazardous to workers trying to direct and control them with such equipment. Animals that are unaccustomed to confinement frequently balk at entering confining structures and may even panic. Also, after being restrained, an animal may spontaneously react by kicking, trying to climb up or back out, and the like. Many of the prior art animal working structures provide little or no protection from such hazards.
Squeeze chutes can be provided with hydraulic power systems for opening and closing their gates and for constricting and expanding their sidewalls to reduce or expand the size of the enclosure in which animals are received. Such hydraulic power systems have the advantage of permitting control of the operable components of the chute from a control station which can be equipped with lever-actuated hydraulic valves on one side of the chute. However, powered operations of many previous squeeze chutes tended to be relatively noisy. For example, noise levels of previous hydraulically-powered squeeze chutes could reach levels of approximately 100 decibels. Such noise levels can interfere with the safe and efficient operation of a squeeze chutes. Firstly, relatively loud noises tend to fatigue the operators, who often are subjected to such noise for many hours at close range during a normal working day. Secondly, the livestock being processed can be startled or panicked by strange, loud noises, such as those made by many previous squeeze chutes. Thirdly, operators can have difficulty communicating over such loud noises. Since commands must sometimes be given to initiate the operation of relatively heavy machinery, the ability of the operators to communicate can be an important safety consideration. Thus, excessively loud squeeze chutes tended to be somewhat unsafe and physically tiring to operate, while contributing to the difficulty in handling frightened animals.
Another problem with many previous squeeze chutes relates to the operation of their gates. Such gates often include pairs of panels which are pivotally mounted on the squeeze chute frame or superstructure in such a way that the gate panels generally traverse arcs which tend to swing the panels into the faces of the animals and thus contribute to their stress and sense of distress.
What is needed is an animal working apparatus that provides working accessibility to an animal confined therein while assuring relative safety and comfort for both the confined animal being worked and those working the animal.